halving vs trichotomy

halving

noun
  • The process or instance of dividing in half. 

trichotomy

noun
  • Division or separation into three groups or pieces. 

  • the property of an order relation whereby, given an ordered pair of elements (of a given algebraic structure), exactly one of these is true: the first element is 'less than' the second one, the second is 'less than' the first, or the two elements are equal. 

How often have the words halving and trichotomy occurred in a corpus of books? (source: Google Ngram Viewer )